An electrochemical measuring cell of the above type is disclosed in European Patent Application No. A2 0077054. This measuring cell includes a first electrode arrangement which is sealed off with respect to the ambient by means of a diffusion membrane. The first electrode arrangement is surrounded by a second annular electrode with the corresponding counter electrode mounted on the rearward end of the head of the measuring cell. The ancillary electrode arrangement can, for example, be utilized to record bio-electrical quantities (Electrocardiogram).
In the known transducer, the ancillary annular electrode is held in a threaded ring disposed in surrounding relationship to the measuring head. Consequently, the measuring cell has such a size that it is unsuitable for placement in smaller openings. Furthermore, with the overall size otherwise being the same, the adhering surface for attaching the measuring cell to a support such as the skin of a person or the hide of an animal is reduced in such a manner that a reliable adherence is no longer assured for difficult conditions which often occur in practice.